Photographic-printing process



J. E. THORNTON.

PHOTOGRAPHIC PRINTING PROCESS.

APPLICATION FILED JULY 3, I919.

Patented Nov. 14, 1922.

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PHOTOGRAPHIC PRINHNG PROCESS.

APPLICATKUN FILED JULY 8.1919.

Patented Nov. 14, 1922.

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UNITED STATES PATENT OFFICE.

JOHN EDWARD THORNTON, OF WEST HAMPSTEAD, LONDON, ENGLAND, ASSIGNOR TO JOHN OWDEN OBRIEN, OF MANCHESTER, ENGLAND.

PHOTOGRAPHIC-PRINTING PROCESS.

Original application filed March 21, 1916. Serial No. 85,702. Divided and this application filed July 8, 1919. Serial No. 309,373.

To all whom it ma, concern:

Be it known that J OHN EDWARD THORN- 'roN, a British subject, residing at West Hampstead, London, England, have invented certain new and useful Improvements in and Relating to Photographic-Printing Processes, of which the following is a specification.

The invention relates to the production of kinematograph films in heliochrome or multi-colour.

The object of the invention is to produce transparent continuous kinematograph films of indefinite length for optical projections by a combination of photo-chemical printing which produces a grainless pattern and photo-mechanical printing which produces a screen pattern, the grainy pattern, by superimposing the photo-mechanical printing of some of the colours upon a film already photo-chemically printed with the complete pictures or one of the colours in a monochrome of black, grey or colour.

The accompanying drawings illustrate films made in accordance with the present invention and also diagrams indicating the color characteristics of the films.

Figure l is a perspective view of a section of film made in accordance with the present invention and having three colors printed in superimposed relation on the front thereof, the back of the film being unprinted;

igure 2 represents, on an enlarged scale, a cross section of the film as shown in Figure 1 F ighre 3 is a perspective view of a section of film also made in accordance with the present invention having two colors on tle front and two colors on the back there- 0 Figure 4 represents a face view of a section of the film shown in Figure 3, illustrating how the colors of the film will appear when the film is held up to the light; Figure 5 represents, on an enlarged scale, a cross section of the film represented in Fi ures 3 and 4; and

igures 6, 7, 8 and 9 are diagrams representing the different color sensations as the eye would see them if a series of landscape or portrait ictures were printed from three plates or lm belts, the colors, however, being thoroughly mixed instead of appearing in isolated squares, as represented in these diagrams.

In carryin out the invention I utilize an original picture for each separate colour, produced by any of the various methods known for obtaining separate colour negatives or positives preferably that known as screen plate photography, and prepare or produce from each a set of photo-mechanical printing belts, one for each colour, as described in U. S. Letters Patent No. 1,361,783.

The transparent continuous kinematograph film is prepared with a sensitive surface and upon this I print an image photochemically in black, grey or colour, which will yield a very sharp, clear image of the Whole picture or of one colour of the picture, and superimpose thereon by mechanical printing from the printing belts the partial images in their respective colours in broken tone markings of dots or lines. The pictures may be taken on two or three separate films or as sequent groups on a single film, thus producing an original picture film for each colour and in this case a printing belt will be produced from each original plcture film or sequence as in the case of a single colour or monochrome original, or the pictures may be photographed on a single film by the process known as screen plate photography.

Screen plate colour photography is to be defined for the purpose of the present invention as the method described under this heading in an article commencing on p. 468 of Cassells Cyclopaedia of Photography, published in the year 1912, also in Farben-photographie mit F arbraster Platten by Mr. Mebes, published in 1911 by F ernbach of Bunzlau.

In preparing printing belts from the original picture film, more particularly of the individual elemental colours, two or more of such printing belts may be made from each, one lightly exposed for the dense parts and the other fully exposed for the lighter tones. By printing from one or the other of these printing belts or from both in succession a high degree of tint is reached and desirable or special effects for harmonising harshness or other defects becomes practicable. Or one of such printing belts may be used for printing say a light shade or tone of blue or a greenish blue, and another for printing a deep blue or a purple blue to give better efl'ect to the colours in the picture. This mode of operation is regarded as of special importance in relation to originals produced by the twocolour process.

' The printing from the original picture film produced by screen plate photography as above described which is a screen-platefilm of two, three, or more colours is done directly or indirectly through a sequence of appropriate colour filters one for each colour upon a corresponding number of prepared strips.

The colours in the original picture film are thus analyzed out and separate printing belts prepared for each colour. Thus from a three colour original picture film threeseparate printing belts are produced each carrying the section or part of the picture in one colour.

It will thus be seen and understood that instead of printing the kinemato raph film wholly by the mechanical met ods and printing belts described in the patent above referred to, the film may be partially printed over a key picture, or over a sin le colour picture previously hoto-chemica ly printed on the film in or er to secure results of better qualit and with greater sharpness of detail, The photo-chemically printed key picture will preferably be grey instead of black to avoid over-powering the colours subsequently superimposed thereon. Or the key picture may correspond to one of the elemental colours of the heliochrome picture. Alternatively this key may be the blue picture or element on which such blue picture may be produced by the well known iron process whether direct or throu h the intermediary of a silver image.

Be erring to the accompanying drawings, the length of film AB of the film shown in Figure 1 is without printing; the section or len th B-G represents the first color printe photo-chemically h light, and colored blue, it extendin from l to E; C-- D represents a section 0 the film on which two colors have been printed, the photochemical blue section upon which is superimposed the red section, the latter being printed photo-mechanically, or without light, and extending from C to E and D-E represents three colors printed on the film, i. e., the photo-chemical blue and photomechanical red and the photo-mechanical yellow, the yellow extending from D to E. The film as shown in Figure 1 is shown in cross section in Figure 2, it comprising a transparent film base 1 of celluloid or other transparent material on which is superimposed the blue section 2 of the picture which is printed photo-chemically and without grain, 4.- re resents the red section of the picture whic is printed in minute dots of color deposited upon the section or layer 2, and 5 represents the yellow layer or section which is printed in dots of color deposited upon the layer 4. These different colors are represented in this figure b difierentiated shade lines.

In igure 3 where the film has two colors on the front and two colors on the back, the photo-chemical print in blue is duplicated on both sides of the film, while the photo-mechanical red is superimposed on one side and the photo-mechanical yellow is superimposed on the other side. In this figure, the length B-C represents the part printed photo-chemically in blue only on one side, while the length E-F represents the part printed photo-chemically in blue only on the opposite side of the film, the length UD is printed on the face of the film with the photo-chemical print in blue and with the photo-mechanical print in red, and the length D.E on the back of the print is printed photo-chemically in blue and photo-mechanically in yellow. By referring to Figure 5 it will be seen thatthis film comprises a film base 1 of celluloid or other transparent material, the blue layers or sections 2, 2 on opposite sides of the base, these being exactly alike and printed photo-chemically, without grain, by light from the same negative at one exposure, is represents the red section of the icture which is printed in -minute dots rom a printing plate or belt b photo-chemical means, the image being 0 the grainy type, and 5 represents the yellow section printe in a manner similar to the printing of the section 5 in Figures 1 and 2. Figure 4 represents how the red, blue and yellow in a film like that shown in Figures 3 and 5 will appear or be visible when the complete film is held up to the light. When the film is viewed in this way or by transmitted light, the series of complete pictures composed of all three colors are seen and they are formed by two identical blue images, a red sectional image superimposed upon one side, and a. yellow image on the other side.

Figures 6 to 9 inclusive represent diagrammatically the different color sensations as the eye would see them, if a series of landscape or portrait pictures were printed from three plates or film belts, in which case the colors would be thoroughly mixed instead of being in isolated squares, as represented in the diagram. These colors would appear as follows: Of the primary colors, red would appear as indicated by the shaded portions 6 in Figure 6, blue would appear as indicated by the shaded portions 7 in Figure 7, and yellow would appear as indicated by the shaded portions 8 in Figure 8. The secondary colors obtained by superimposition of two colors, as is indicated in Figure 9, would appear as indicated by the shaded portion 10 as orange, 11 as green and 12 as purple. Black obtained by superimposition of three colors is designated by the area 13 in Figure 9, and white obtained by light passing through the bare portions of the transparent base and which are free from color is designated by the area 14 in Figure 9.

Instead of using a toned silver image for one section of a colour picture such photographic image may be printed by the carbon-bichromate or by the pinatype dyedbichromate. method, whereby the colour is obtained by direct development without subsequent toning). The same methods may be adopted for a lack or grey key.

To ensure accuracy of registration of the several superimposed images all films for negatives or positives are accurately perforated by the same machine, and the printing belts that app] the greasy-ink images are likewise per orated to correspond. Shrinka e of the film carrying the photographicifily printed image is compensated for by suitable adjustments of the relative positions when applying the superimposed ima hat I claim as my invention and desire to protect by Letters Patent is:

1. A process of producing continuous kinematogra h positive films with a series of heliochrome aving an absolutel sharp and consists in preparing an original continuous series heliochrome picture by photographing in a camera by the multi-color screen method, printing from the original picture photo-chemically onto a sensitive final positive film to produce thereon parts of a heliochrome having an absolutely sharp and grainlessimage, and printing other parts of the original picture in color and in superimposed relation onto said image by a photo-mechanical screen pattern or rainy pattern process to complete the helioc rome positive.

2. A continuous kinematograph positive heliochrome film, comprising a grainless full tone image forming one part of the heliochrome, and other images of a grainy or half-tone pattern of dot, line or mosaic formation superimposed thereon and formin the other or completing part of the he iochrome.

3. A kinematograph positive heliochrome film comprising a grainless full-tone image, and other i ages in colors so erimposed thereon whic are of a grainy ha f-tone pattern of dots lines or mosaic formation, the whole combination of superimposed printings givin the effect of a multicolor grainy print whic is sharpened in outline by the grain image.

4; he process of producing continuous kinematograph positive heliochrome films from colour elements analyzed out from an original multi-colour screen film, which comprises printing from each element separately in a different colour or shade, onto a sensitized film by superimposition methods, some of said printings being made by photochemical means and some by photo-mechanical means, thus giving a combination of photo-chemical and photo-mechanical processes.

5. A process of producing continuous kinematograph positive films with a series of heliochrome pictures printed thereon which comprises preparing an original picture film, printing part of the colors of the heliochrome onto a sensitized film from said original picture film by a photo-chemical process to secure an absolutely sharp and grainless image, preparing color elements from said origina picture film, and printing other colors onto said sensitized film from said color elements and in superimposed relation by a photo-mechanical screen pattern or grainy pattern process, thus producing a positive series strip on which the colors are printed as superimposed layers.

6. A process of producing kinematograph heliochrome positive films bearing series of pictures in natural colors, which consists in taking the original heliochrome or camera picture upon a multi-color screen film, making therefrom full-tone reproductions in the form of printing belts, one printing belt being provided for each color, shade or section, printing part of the colors of the heliochrome onto the final film by a grainless photo-chemical process, and printinga color, shade or section from each printing belt onto the final film by a photo-mechanical grainy pattern or screen pattern process.

he process of producing kinematograph heliochrome positive films by superimposed printing processes from heliochrome originals made by the multi-color screen process, which consists in making a set of intermediary analyzed single color reproduced cliches of full-tone character without dots, lines, mosaic or other pattern and with the images extending over the entire area of each picture, printing part of the colors of the heliochrome from said cliches onto a sensitized film by a photochemical process to secure an absolutel sharp and grainless image in the final positive, preparing photo-mechanical printing belts from said cliches, and printin other colors of the heliochrome from said printing belts onto said sensitized film by a; photo-mechanical screen pattern or grainy process.

8. A complete kinematograph heliochrome positive film of the superimposed type consisting of one piece of film stock having photo-chemically printed thereon a full tone grainless ima e in one color and having superimpose thereon another color section image, in another color, of the halftone grainy type and composedof mechanisaid prints being in different colors and of 10 call applied coloring matter attached to the different color values. sur ace of the film stock in which'the first In testimony whereof I have hereunto photo-chemical image is embedded. set my hand in presence of two subscribing 9. A continuous kinematograph helio- Witnesses. chrome positive film in a plurality of color JOHN EDWARD THORNTON. printings, comprising a photo-chemical Witnesses: foundat on print and a succession of photo- J. OWDEN OBRIEN, mechanical prints superimposed in registry, N. J. A. HORBWORTH.

Patent No. 1,435, 759.

CERTIFICATE or common.

Granted Novenflaer 14,, 1922. to.

JOHN 201mm) women;

It is hereby certified that error appear: in the printed epecificetion of the above numbered potent requiring correction as iollowe: Page 3. line 31, claim 1, strike out the words "havingnn absolutely slurp and" and insert instead "pictures p'rinted thereon, which"; and that the said Letters Patent lbonld be read with this correction therein that the name my conform to the record of the case in the Patent Oiii'ce. r

Signed and sealed this 17th do 0! July, A. b.1928.

llllioore.

(Sell) Acting Commissioner of htente. 

